1. Field of the Invention
The present invention relates to a lock unit comprising at least one catch having a primary position and a first position, wherein the movement of the catch is blocked by at least a pawl, in the closed position. The invention finds particular application in motor vehicles for locking doors, hatches, etc.
2. Brief Description of the Related Art
Different embodiments of such lock units may be employed. It is possible, for example, that the locking of the catch is accomplished alone in the primary position by the pawl, wherein the arrangement of the catch and the pawl is chosen such that, for example, the contact force between the catch and the pawl is transferred about the pawl axis. Other embodiments are known, in which the pawl is not in a position to lock the catch in the primary position by itself. This is particularly true for the case in which the catch is spring-biased such that it tends to pivot to its open position at all times. In this case, the arrangement between the latch and the catch is such that the contact force between both parts of the locking mechanism is not transferred about an axis of rotation of the pawl, but rather the locking mechanism comprises a component oriented radially outward, which pushes the pawl. To ensure safe locking of the pawl in the primary position of the catch an additional blocking lever can be provided, which blocks the opening movement of the pawl.
In addition, lock units equipped with a so-called self-closing mechanism are known. The self-closing mechanism ensures that when the catch is moved into the first position, it is then actively pivoted from the first position into its primary position by means of a drive, especially an electric motor, while at the same time overcoming the force necessary to close the door against a door seal.
Moreover, it is considered advantageous to detect the closed position of the lock unit, i.e., when the pawl abuts the primary position of the catch, and then to turn on or off various functions of the motor vehicle. For example, in this way, open door indicator lights can be turned on or off on the dashboard. The automatic vehicle interior lighting may also be controlled, depending on the specific position or positions of the locking components, especially the catch and/or the pawl. When appropriate, the engine starter can be disabled until it is determined that all door lock parts of all doors have reached their locked position.
For this purpose, the location of the catch can be detected by means of microswitches. In particular, whether or not the catch has reached its latched position may be detected. Such systems work occasionally, however, with relatively large tolerances and often cannot handle extreme positions of the locking mechanism, such as the overtravel position, which is often realized in self-closing mechanisms. This can leads to misinterpretation of the sensor signals.